.index_box{
    width: 100%;
    height: 100%;
    .top{
        width: 100%;
        height: 100px;
  
    }
    .down{
        margin-top: 20px;
        width: 100%;
        height: calc(100% - 100px);
        .group{
            width: 100%;
            height: auto;
            margin-top: 20px;
            display: flex;
            justify-content: space-around;
            align-items: center;
            flex-wrap: wrap;
        }
    }
}
